Writing for a code base of 1,000,000+ Lines

Writing code for a 1,000 line application is very different from writing for 1,000,000 line application.

When the codebase becomes so large, you simply cannot remember everything.

You rely on naming, conventions, and trust.

Conventions

Understand the conventions already used, and stick to them. It makes it easier to read the code, and get it reviewed.

In a large code base, coding conventions may be different from team to team.

Consistency

Use linters.

Don't waste time discussing style

Use linters.

If a discussion about style comes up, quickly agree on something, and implement it in your linter.

Trust in the code base

You will always be using a library written by someone else. You have to trust that it says it does what it does. If it doesn't, then you have to dive deeper down the rabbit hole.